T-Mech 7.5hp Petrol Rotavator Tiller

I. Installation of the Power Rotavator

Before leaving the factory, the main body of the power Rotavator has been assembled and tested. However, before using the power Rotavator for farming operations, users should inspect and adjust all mechanisms to ensure optimal performance.

After purchase, the user only needs to complete assembly according to the following steps:

1. Install the walking wheels on both ends of the hexagonal drive shaft at the lower part of the gearbox, securing them with φ8 pins.
2. Install the towing arm onto the towing seat, connect it with the towing shaft, and insert the resistance rod.
3. Assemble the armrest bracket with the armrest support arm and secure it using the lifting locking handle.
4. Fix the mudguard bracket onto the engine bracket and trailer, then install the mudguard.

Bolt Inspection:

Check all connecting bolts for looseness and tighten them according to the torque values listed below. For tightening torque of petrol engine bolts and nuts, refer to the petrol engine user manual.

Component Torque (N·M)

Flange and petrol engine 14-19

Flange and Gearbox 27-38

Gearbox main shaft rear-end bolts 10-12

Engine support bracket and travel case bolts 27-38

Travelling mechanism end cover bolts 10.6-15

Travelling mechanism trailer body bolts 27-38

Walking mechanism to gearbox bolts 27-38

Trailer bolts 27-38

Diesel engine base fixing bolts 27-38

Handrail fixing bolts 35-40

Control System Check:

Ensure that all control handles (throttle, clutch, gear shift and reverse gear) operate smoothly without obstruction. Correct any malfunctions found.

Transmission Gear Position:

Place the transmission shift lever in the neutral position.

Engine Oil and Lubrication:

Engine Oil - Fill the engine crankcase with the appropriate amount of oil so that the level is between the upper and lower marks on the dipstick. Refer to the engine user manual for oil specifications and filling procedures. SAE 10W-30 engine oil (CC grade or above) is recommended for general temperature conditions.

Transmission Oil - Use L-AN 46 machine oil in summer and L-AN 32 machine oil in winter. Place the machine on a level surface and fill oil through the oil port above the gearbox. Insert the dipstick without rotating it to check the oil level. The oil should be between the upper and lower marks. Normal filling volume is 1.8L.

Air Cleaner Oil - Remove the lower cover of the air cleaner and add 0.1 litres of clean engine oil.

Diesel Engine Lubricant Selection - Select diesel engine lubricant according to ambient operating temperature.

Fuel Filling:

Fill the petrol engine fuel tank with No. 92 or No. 95 petrol (refer to the petrol engine user manual for details).

ATTENTION - Do not exceed the maximum fuel level.

Pre-start Preparation:

Carry out all pre-start preparations in accordance with the petrol engine operating instructions.

Power Rotavator Adjustment Methods

1. Handrail Installation and Height Adjustment:

* Before adjusting the handrail height, place the machine on a flat and stable surface to prevent accidental tipping.

* Loosen the adjustment handle and set the armrest crossbar to a height approximately level with the operator's waist. After adjustment, firmly tighten the adjustment handle.
2. Rotary Tillage Depth Adjustment:

The depth of rotary tillage is controlled by adjusting the height of the speed control lever:

* Lowering the lever increases the rotary tillage depth.

* Raising the lever decreases the rotary tillage depth.
3. Clutch Use and Adjustment:

Before operating the clutch, reduce the engine speed. The clutch 'ON' and 'OFF' control is used to engage and disengage engine power.

* When the clutch handle is released, the clutch disengages, engine power is cut off and the rotary blades stop rotating.

* When the clutch handle is fully squeezed, the clutch engages and power is transmitted to the power Rotavator, causing the rotary blades to rotate.

Attention: Improper clutch cable adjustment may affect normal operation.

Clutch Cable Tension Inspection:

* Under normal conditions, the clutch cable free play should be 4-8mm.

* If the free play is outside this range, loosen the locking nut and adjust accordingly.

* After adjustment, tighten the locking nut securely.

* If necessary, start the engine and very correct clutch operation.
4. Throttle Cable Adjustment:

Normal speed range:

* Idle speed: 1600 ± 150 rpm

* Maximum speed: 3600 rpm

Speed adjustments should be verified using a tachometer.
5. Speed Checking Method:

* With no load applied, turn the throttle switch on the armrest to the maximum position and confirm that the tachometer reads approximately 3600 rpm.

* Turn the throttle switch to the minimum position and confirm that the tachometer reads 1600 ± 150 rpm.

If the speed is not within the specified range, adjustments to the petrol engine are required as follows:

* Check the throttle cable for looseness or detachments and secure it properly.

* With no load, set the throttle switch to the maximum position and adjust the speed regulating bolt on the petrol engine throttle control assembly to the correct position.

* After extended operation, fine adjustments can be made using the throttle cable fine-adjustment bolt.
6. Handrail Height Fine Adjustment:

* Loosen the lifting lock handle by hand.

* Adjust the armrest frame to a height suitable for the operator and re-tighten the locking handle securely.
7. Bevel Gear Pair Adjustment Method:

If abnormal transmission behaviour or excessive noise is detected in the gear system, inspection and adjustment are required.

Bevel Gear Pair Adjustment in the Gearbox -

* When gear backlash is less than 0.05mm, add a steel shim between the gearbox and the travel box to increase the backlash.

* When gear backlash is greater than 0.30mm, add a steel shim between the bearing and Gear ll to adjust the axial clearance to 0.05-0.10mm.

Bevel Gear Pair Adjustment in the Walking Box -

* When the backlash is less than 0.05mm, add adjustment shim l (0.2-0.03mm) to increase side clearance. Replace steel shim ll and adjustment shim IT as required to ensure that the axial clearance of Gear ll is 0.05-0.15mm.

* When the backlash is greater than 0.30mm, reduce adjustment shim l while maintaining the axial clearance of Gear ll at 0.05-0.15mm, or increase adjustment shim ll while ensuring the axial clearance of Gear l remains 0.05-0.15mm.

ATTENTION: The power Rotavator must be properly run in before use. Refer to Chapter 6 for break-in procedures.

Engaging Low Gear:

1. Release the clutch handle with your left hand to disengage the clutch.
2. Pull the gear shift lever backward with your right hand to the low-gear position and ensure it is fully engaged. Then hold the appropriate handrail with your right hand (do not hold the reverse gear handle).
3. Slowly squeeze the clutch handle so the clutch engages and the power Rotavator begins to move at low speed.
4. Gradually increase the throttle with your right hand to operate at the desired low speed.

Engaging High Gear:

1. Release the clutch handle with your left hand to disengage the clutch.
2. Push the gear shift lever forward with your right hand into the high-gear position, ensuring it is fully engaged. Then hold the right arm rest (do not hold the reverse gear handle).
3. Slowly squeeze the clutch handle to engage the clutch, allowing the power Rotavator to move backward (do not release the reverse gear handle during operation).
4. When reversing is no longer required, slowly release the clutch handle with your left hand and then release the reverse gear handle with your right hand.

Gear Shifting During Operation:

When changing gears whilst moving, first reduce the petrol engine throttle (without allowing the engine to stall), then disengage the clutch and shift gears only after the machine has stopped moving.

Steering:

To steer, gently swing the armrest to the left or right.

CAUTION: Do not grip the wrong handle while turning, as this may damage the gearbox.

Parking:

1. Release the clutch handle to disengage the clutch.
2. Shift the gear level to the neutral position, then turn the ignition switch to the OFF position to stop the petrol engine.
3. When stopping the petrol engine, follow the procedures described in the petrol engine instruction manual.

Note: The power Rotavator should generally be stopped on level ground.

Connection and Use of Auxiliary Equipment:

When rotary tillage is required, remove the walking wheels and install the hexagonal tube of the rotary Rotavator onto both ends of the walking mechanism drive shaft. Secure it axially using small pin shafts.

Attention:

1. Rotary Rotavator blades are divided into left and right groups. Ensure that the blade edges face forward during operation.
2. After installing the rotary Rotavator blades, left and right mudguards must be installed to prevent personal injury.
3. The rotary tillage depth can be adjusted by changing the blade height and the angle between the blades and the ground.

Precautions for Power Rotavator Use:

1. During operation, pay close attention to machine performance and sound. Check all connections regularly and stop immediately if abnormalities are detected.
2. Do not operate under heavy load immediately after a cold start, especially new machines or machines after overhaul.
3. Regularly check the oil levels of the petrol engine and gearbox, and replenish oil promptly when levels are low.
4. Do not cool the petrol engine by pouring water onto it.
5. Prevent the power Rotavator from tipping over during ploughing.
6. It is strictly prohibited to operate the power Rotavator with rotary Rotavator blades installed on sandy beaches or gravel surfaces to avoid blade damage.
7. After use, remove soil, weeds, oil and dirt from the power Rotavator and keep the machine clean.
8. Clean the sponge or metal mesh in the air filter regularly and replace the oil as required.

Problem: Fast, Slow, or Neutral Gears Not Engaging

Possible Causes

• Bolts or round nuts at the rear of the main shaft are loose.

Solution

1. Remove the bolts, key sleeves, and locking nuts from the rear of the main shaft.
2. Reinstall the key sleeves and bolts securely, then tighten all components to specification.

Problem: Poor Gear Engagement

Possible Causes

• Pull block is worn.
• Bevel drive gear is loose.
• Connecting block on support arm is worn.
• Internal positioning spring on the spindle is damaged.
• Gland bolts at rear of gearbox are loose.
• Shift lever is bent or deformed.

Solution

1. Replace any worn pull block or positioning spring.
2. Tighten the round nut on the bevel gear.
3. Replace worn support arm assembly.
4. Tighten all rear gland bolts on the gearbox.
5. If the shift lever is bent, correct or replace it.

Problem: Reverse Gear not engaging

Possible Causes

• Reverse gear fork is worn.

• Reverse gear cable is damaged or misadjusted.

• Reverse gear shaft is loose.

• Reverse gear fork is jammed.

Solution

1. Readjust or replace the reverse gear cable.
2. Tighten the rear bolt on the reverse gear shaft.
3. Clean the contact surfaces between the reverse gear fork shaft and push plate to ensure smooth movement.

Problem: Reverse Gear Does Not Return to Neutral

Possible Causes

• Reverse gear shaft is loose, causing gear lock.
• Return spring on the reverse gear shaft is damaged.
• Reverse gear shaft is bent or deformed.

Solution

1. Tighten the rear bolt on the reverse gear shaft.
2. Replace the spring if worn or broken.
3. Replace the reverse gear shaft if bent.

Problem: Excessive Gear Noise

Possible Causes

• Deformation or bending of the bevel or reverse gear shafts.
• Excessive wear or incorrect backlash in the gears.
• Gears or shafts fit too loosely in the housing.

Solution

1. Replace worn or bent gears and shafts.
2. Check and adjust gear backlash according to specifications.
3. Replace any loose or damaged housing components.